new command: into column_path (#4048)

crates/nu-command/src/commands/conversions/into/column_path.rs

@@ -0,0 +1,118 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{ColumnPath, Primitive, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct SubCommand;
+
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "into column_path"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("into column_path").rest(
+            "rest",
+            SyntaxShape::ColumnPath,
+            "values to convert to column_path",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Convert value to column path"
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        into_filepath(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Convert string to column_path in table",
+                example: "echo [[name]; ['/dev/null'] ['C:\\Program Files'] ['../../Cargo.toml']] | into column_path name",
+                result: Some(vec![
+                    UntaggedValue::row(indexmap! {
+                        "name".to_string() => UntaggedValue::column_path("/dev/null", Span::unknown()).into(),
+                    })
+                    .into(),
+                    UntaggedValue::row(indexmap! {
+                        "name".to_string() => UntaggedValue::column_path("C:\\Program Files", Span::unknown()).into(),
+                    })
+                    .into(),
+                    UntaggedValue::row(indexmap! {
+                        "name".to_string() => UntaggedValue::column_path("../../Cargo.toml", Span::unknown()).into(),
+                    })
+                    .into(),
+                ]),
+            },
+            Example {
+                description: "Convert string to column_path",
+                example: "echo 'Cargo.toml' | into column_path",
+                result: Some(vec![UntaggedValue::column_path("Cargo.toml", Span::unknown()).into()]),
+            },
+        ]
+    }
+}
+
+fn into_filepath(args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let column_paths: Vec<ColumnPath> = args.rest(0)?;
+
+    Ok(args
+        .input
+        .map(move |v| {
+            if column_paths.is_empty() {
+                action(&v, v.tag())
+            } else {
+                let mut ret = v;
+                for path in &column_paths {
+                    ret = ret.swap_data_by_column_path(
+                        path,
+                        Box::new(move |old| action(old, old.tag())),
+                    )?;
+                }
+
+                Ok(ret)
+            }
+        })
+        .into_input_stream())
+}
+
+pub fn action(input: &Value, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    match &input.value {
+        UntaggedValue::Primitive(prim) => Ok(UntaggedValue::column_path(
+            match prim {
+                Primitive::String(a_string) => a_string,
+                _ => {
+                    return Err(ShellError::unimplemented(
+                        "'into column_path' for non-string primitives",
+                    ))
+                }
+            },
+            Span::unknown(),
+        )
+        .into_value(&tag)),
+        UntaggedValue::Row(_) => Err(ShellError::labeled_error(
+            "specify column name to use, with 'into column_path COLUMN'",
+            "found table",
+            tag,
+        )),
+        _ => Err(ShellError::unimplemented(
+            "'into column_path' for unsupported type",
+        )),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ShellError;
+    use super::SubCommand;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-command/src/commands/conversions/into/mod.rs

@@ -1,4 +1,5 @@
 mod binary;
+mod column_path;
 mod command;
 mod filepath;
 mod filesize;
@@ -7,6 +8,7 @@ pub mod string;
 
 pub use self::filesize::SubCommand as IntoFilesize;
 pub use binary::SubCommand as IntoBinary;
+pub use column_path::SubCommand as IntoColumnPath;
 pub use command::Command as Into;
 pub use filepath::SubCommand as IntoFilepath;
 pub use int::SubCommand as IntoInt;

crates/nu-command/src/default_context.rs

@@ -138,6 +138,7 @@ pub fn create_default_context(interactive: bool) -> Result<EvaluationContext, Bo
             whole_stream_command(Insert),
             whole_stream_command(Into),
             whole_stream_command(IntoBinary),
+            whole_stream_command(IntoColumnPath),
             whole_stream_command(IntoInt),
             whole_stream_command(IntoFilepath),
             whole_stream_command(IntoFilesize),